Paper cup



Aug. 18, 1942. v w. AMBERG PAPER CUP Filed Oct. 5. 193a 1N VENT OR.Walter E Jmbefg,

ATTORNEY.

Patented Aug. 18, 1942 PAPER CUP Walter E. Amberg, Chicago, 111.,assignor' to Universal Paper Products Company, Chicago, 11]., acorporation of Illinois Application October 5, 1938, Serial No. 233,345

(craze-1.5)

4 Claims.

This invention relates to a new and improved type of paper cup and moreparticularly'a coneshaped paper cup suitable for use in dispensingwater, soda and other liquids.

One of the objects of the invention is to provide a paper cup which canbe made from a strip of paper with a minimum amount of material and verylittle waste.

Another object is to provide a new and improved type of paper cup whichcan be. formed rapidly and continuously on a cup machine from acontinuous roll of paper. Other objects will appear hereinafter; 2 Theseobjects are accomplished in accordance with this invention by theprovision of a coneshaped cup formed from a blank comprising a convexside, a concave side and a straight side arranged to intersect eachother. The convex side and .the concave side have the same radii ofcurvature and are spaced apart on a line joining the centers ofcurvature a distance substantially greater than the radius of curvature.The straight side of the blank is substantially parallel to or coincideswith the line joining the centers of the radii of curvature of theconvex and concave sides.

I This blank is formed into a cup by rolling it or winding it around thecenter of curvature of the convex side as the apex of the cone so thatthe convex side forms the periphery of the cup and portions of the blankadjacent the concave side together with portions of the blank adjacentthe straight side are overlapped and form 'a part of the side wall ofthe cup. In forming such a cup the center of the radius of curvature ofthe convex side-may be on the straight side,

but it is preferable in accordance with this invention that said centerbe within the blank and that the blank be wound or rolled in such amanner as to form anunderlying pocket of material at the apex, therebyrendering the cup leak-proof. The position of the center of curvature ofthe convex sideis preferably such that the edges of any underlyingpocket of material do not project beyond the confines of the overlappingportion when the cup is formed around said center as the apex of thecone.

Other features and advantages of the invention will become apparent froma reading of the following specification in the light of theaccompanying drawing in which:

Figure 1 shows a strip of paper having dotted lines toindicate themanner in which the blank is cut; a

shown in Figure 1 illustrating a preferred manner of winding the blankinto a cone-shaped cup;

Figure 3 is a side elevational view of the completed cup;

Figure 4 is a view of the apex portion of the cup showing a preferredform of construction;

Figure 5 illustrates a modified method of forming cups and blanks asherein described.

As illustrated in Figure 1, the blanks are severed successively from astrip of paper 2 along lines 4, 6 and 8. Prior to severing the blanksadhesive is applied to portions of the paper strip as, indicated atnumerals l0, l2 and It.

Paper strip 2 is advanced beneath a conical former l6 which-is rotatingagainst a flat surface in an orbit having its center of curvature at pint I8.

As illustrated in Figure 1, the center point I8 is also the center ofthe are 6 which defines the convex side. of the blank. Conical former I6is provided with a cutting edge 20 and also with any suitable means forgripping the side of paper strip 2. Hence, as said former rotates in itsorbit it grips the side of paper strip 2 and immediately thereafter, orsimultaneously therewith, the cutting edge of said former begins to cutthe paper strip along line 6 and roll it into a cone-shaped receptacle.The straight edge 22 of blank A is carried by the former, as illustratedin Figure 2, and is rolled or wound on the former until it substantiallycorresponds .with line 24 at which point it is overlapped by the gluedportion l0 and the resultantcone shaped cup is discharged from theconical means of air or a mechanical ejector. During the formation ofthe cup the blank A may be held on the former in any suitable manner,as, for instance, by vacuum orby mechanical grip- 40 pers. Shortly afterthe cup is formed it is discharged while the conical former continues inits orbit. In the meantime the strip of paper 2 is fed forward into theorbit'of conical former l6 so that the center 260i the radius ofcurvature of convex side 8 is substantially at the apex then forms a cupfrom blank B in the same manner as just described for blank A. Thus, aseries of cups is successively formed from a continuous strip of paperwith only a small amount of,

waste as represented by the areas 28 and 30.

Figure 2 is a view of a portion of the strip In Figure 1, line CCconnects the centers of ormer in any suitable manner, for example, by

formed.

lines 4, 6 and 8 and said lines are spaced apart on center line CC adistance which is greater than their radii of curvature. Thus, referringto blank A, it will be seen that as the cup is formed line B, whenappropriately cut by conical former I6, becomes the convex side of theblank and forms the periphery of the cup, line 4 becomes the concaveside and line 22 becomes the straight side. These sides are alsoarranged as to intersect each other and to form a three-sided blank.Actually of course, according to the method described, no blank isformed prior to the formation of the cup. This method of making cupsdiffers radically from methods heretofore in use which involve cuttingthe blank before the formation of the cup. One of the features of thepresent invention resides in the fact that the cup is formed from astrip of paper without changing the direction of the material from whichthe cup is In some methods heretofore in use, where the cup has beenformed from a continuous strip of paper, it is absolutely essential tosever the paper before beginning the formation of the cup because whenthe former grips the material to be formed into a cup, it changes thedirection of said material. According to the present invention no suchchange of direction is necessary. The former, as previously explained,rolls in an orbit against a fiat surface which may be provided with acutting knife conforming to the curvature of the orbit and adapted tocooperate'with cutting knife 20 on conical former it.

The construction of the apex of the cup is illustrated in more detail inFigure 4. As shown in Figure 4, when the paper is wound onto the conicalmandrel a pocket of material 32 is formed just beyond the apex It. Thispocket of material contains no adhesive but is overlapped and held inplace by adhesive coating Ill. The position shown in Figure 4corresponds to that which obtains when the material A has been wound onconical former l to the point where straight edge 22 coincides with line24 and is just about to be overlapped by curved edge 4 containingadhesive coating in. As material A continues to be wound upon conicalmandrel I6, adhesive coating III will overlap and coincide with area 34.

According to one of the preferred embodiments of the invention it hasbeen found that unusually good results may be obtained by coating area34 with a dried coating of adhesive, usually referred to as aremoistem'ng adhesive. Area I8 is coated with a, wet adhesive which isapplied to the top side of paper strip 2 at some point prior to thepoint where said strip passes beneath mandrel l6 but sufficiently closethat the adhesive does not become dry before the cup is formed.The-dried coating 34 on the other hand is applied to the under side ofthe paper along straight edge 22 at such a point that it issubstantially dry before the cup is formed. When the wet coating ofadhesive is brought into contact with the dried coating of adhesive, anunusually strong bond is obtained.

It will be understood that small portions of the paper ordinarilyforming the cup may be removed by clipper knives or in any othersuitable manner while the cup. is being formed. For example, if desired.corner portions 36 and 38 may be cut 01! along straight or curved lineswithout departing from the invention.

While, according to the preferred construction, the centers of'curvatureof lines 6 and 8 are substantially within the strip of material, asillustrated in'Flgures 1 and 2, it isalso possible to i of Figure 4. Inthe modification described in curvature of said lines are on the edge ofstrip .2. This is illustrated in Figure 5 in which the center ofcurvature l8 of line 6' adapted to formthe convex side or periphery ofthe cup is on the straight edge 22', thus providing'a cup in which theblank A has a concave side 4', a convex side. 6', a straight side 22'and a point l8 adapted to form the apex of the cup and which is also thecenter of curvature of the side 6'. In this, type of cup the adhesivelycoated area l0 overlaps the straight edge 22 but there is no pocket ofmaterial at the apex, as illustrated by portion 32 Figure 5 the linejoining the centers of curva ture of the concave and convex sidessubstantially coincides with the edge of the strip.

It is preferable, in accordance with the present invention, that theconical mandrel i6 pick up the paper strip 2 along straight edge 22.This permits the mandrel [6 to grab or hold a maxi mum area of the paperstrip and furthermore, brings the mandrel in contact with the edge ofthe paper strip along substantially the entire length of the mandrel atapproximately thesame time, thus making it possible for the mandrel tograb and hold the strip more tightly. It will be understood, however,that instead of moving the mandrel in a counterclockwise direction, asshown in Figure 1, it may be moved in its orbit in the oppositedirection, in which event, however,-

mandrel It would pick up curved edge 4 and the glue areas I a, 02 and Idof Figure 1 would be applied along straight edge 22 on the top side ofthe advancing strip, thus placing curved edge 4 within the blank ratherthan outside, as previously described. I

While the glue areas are shown in the drawing as being applied along theedge of the paper, it will be understood that it is customary inpractice to leave a margin free from glue in order to' keep the gluefrom extending beyond the edges when they are overlapped.

The expression center of curvature of the convex side within theconfines of the blank" is employed herein generically to include andcover a blank in which said center is on the edge of the blank as wellas one in which the center is substantially inside of the blank. Theexpression substantially parallel is used generically herein to covercoinciding lines as well as lines which are side by side. The expressionsides arranged to intersect each other is intended to cover anarrangement of sides which actually intersect or which would normallyintersect except for the removal of portions of the blank in thetrinmediate proximity of the points of intersec- Having thus describedthe invention, what I claim as new and desire to secure by LettersPatent of the United States is:

1. A three sided blank for forming a coneshaped paper cup having asubstantially true conical form, said blank being unsymmetrical in arcadapted to form the mouth of the cup and having its center of curvatureat a point within the confines of the blank, a straight side, a con.-

cave side Joining said straight and convex sides and formed from a,single arc having the same v radius as the convex side with its centerof cutvature outside of the blank, the straight line Joining the centersof curvature of the convex and concave sides being parallelto andadjacent v lapping to form a sea the said straight side, said center ofcurvature of the'convex side being nearer the concave side than theconvex'side as measured along said straight line Joining-the centers ofcurvature of said side's adapted to lie substantially at the apex whenthe blank is wound into a cup, said center of curvature being sopositioned with relation to the concave side and the straight side thatan under-lying pocket of material is formed when said sides areoverlapped without projecting beyond the confines'of the overlappingportion.

2. A cone-shaped cup having a substantially true conical shape formedfrom a blank of flexible sheet material of an unsymmetrical generallytapering configuration comprising three sides arranged to intersect eachother, one of said sides being a convex side with its center ofcurvature within the confines of the blank, another of said sides beinga concave side with the same radius of curvature as the convex side andwith its-centerof curvature outside of the blank,

said convex and concave sides extending a short distance beyond astraight line joining the centers of curvature and intersecting thethird side which is substantially parallel to said line joining thecenters of the radii of curvature, said blank being wound into acone-shaped cup with the apex substantially at the center of curvatureor the convex side and the other two sides overin the side walls of thecup with a pocket 0 material in said seam J adjacent the apex.

3. A three sided blank for forming a vessel I having substantially atrue conical shape, said blank being unsymmetrical in shape of agenerally tapering solid configuration and comprising a body portion andan overlap portion and comprising a lower edge consisting of a singleconcave are, an upper edge consisting of a single convex arc to definethe mouth of the vessel having the same radius of curvature as the loweredge and a side edge which is substantially straight, said side edge andsaid lower edge being .adapted to overlap each other to form a scam inthe side wall of the vessel, and the center of ourvature of said upperedge being within the blank at a point nearer the lower edge than theupper edge as measured along a straight line through the centers ofcurvature of said convex and concave arcs.

4. A cone-shaped paper cup of a substantially true conical shape formedfrom a blank of unsymmetrical tapering configuration comprising a loweredge having a concave arc,an upper edge having a convex arc of the sameradiusvof cur-,

being greater adjacent the apex and adjacent the mouth of the cup thanin the central portion of the side wall.

WALTER E. 'AMBERG.

